The Naugatuck River is located in southwestern Connecticut and was an important part of local Native culture being a primary source of food.

Fish were plentiful in the clean, fast flowing water and the arrival of European settlers did little to change this.   Despite the influx of people, the river and its banks remained pristine and well stocked until the industrial revolution.

The Industrial Revolution

The large buildings are textile mills in this mid 1800’s illustration by Joseph Ropes

Waterbury lies in the basin of the Naugatuck River and had a population of just 5,000 over a century after it was founded, as the lack of suitable farmland discouraged settlers.   In the early 1800’s, this changed rapidly as textile mills, and manufacturing plants were established and a thriving brass industry was born attracting unprecedented numbers of people.

The demands placed on Waterbury’s water supply were immense.   The local population required drinking water, the new industries required water for their manufacturing processes and industrial waste was discharged into the Naugatuck River, as was effluent.

Trout Unlimited

Bob Perella is a board member of the Naugatuck / Pomperaug chapter of Trout Unlimited. “Trout Unlimited is a not-for-profit voluntary organization that is concerned with the health and well being of streams and rivers nationwide, and there are 12 local chapters in Connecticut alone.”

As Waterbury continued to spread there was an urgent need to secure a healthy supply of water.   In 1893, Waterbury was authorized by the Connecticut legislature to take as much water as its inhabitants needed from brooks, rivers, ponds, lakes, and reservoirs within Litchfield and New Haven Counties. Waterbury then built two reservoirs in the basin of Branch Brook, which feeds into the Naugatuck River.

Brook Trout from American Fishes by Goode and Gill (1903)

As the industrial revolution gathered pace so did the demands placed on the river throughout its length and many towns built dams to supply their townsfolk and discharges into the Naugatuck reached unprecedented levels.

Bob continues the story, “Fish in the water are like parrots in coal mines.   When the fish start to suffer and die, then the waterway is in trouble.   Salmon and brook trout were indigenous to the Naugatuck River and their numbers dwindled as the surrounding population, industries and pollution increased.   With passage to their breeding grounds upstream blocked by dams, salmon were unable to reproduce and died out.   Brown trout, rainbow trout and brook trout all require clean healthy water and the pollution reduced the water quality in the Naugatuck to such an extent that they could no longer survive.”

Restoration of the Naugatuck River

In the second half of the 20th Century many of the once booming industries were in decline and the last brass mill in Waterbury closed in the 1970’s.   As these industries receded tourism increased and the Connecticut Department of Environmental Protection (DEP) was established.

The Naugatuck River was in a perilous state and the DEP worked in conjunction with local chapters of Trout Unlimited, the Naugatuck River Watershed Association and other advocacy groups and residents to revitalize the river.   Many dams were removed and where they remained fish ladders were installed.   With their passage now unheeded, fish were once again able to swim upstream.   The poor water quality was addressed by upgrading waste water and sewage treatment plants and requiring industry to stop dumping raw waste into the river.

An Atlantic Salmon
BY & COPYRIGHT: Hans Petter Fjeld

Tributaries were assessed and improvements made as Bob explains. “The DEP evaluates the stretch of river to be improved and provides site specific advice as to what should be done.   Native trees and shrubs are often planted along the banks to prevent the river from becoming wider.   A wide stream will warm more quickly in the sunlight and a reduced tree canopy speeds warming still further.”

Warm water is harmful to fish in a number of ways.   Fish cannot split oxygen from water but rely upon oxygen that is dissolved in water.   Oxygen typically dissolves in water when it aerates when tumbling over falls and rapids and as a waste product of photosynthesis. Oxygen dissolution reduces at higher temperatures and being cold blooded animals, fish use more oxygen at higher temperatures as their metabolic rate increases.   For example, at 41°F, trout use about 50-60 milligrams of oxygen per hour; at 77°F they may need five or six times that amount.

Bob continues “Ensuring that the rivers run clean and cold is vital.   Debris and trash is removed from the stream and water temperatures and PH levels are regularly monitored.   Approximately four years ago, the state mandated that no development should occur within 50 feet of either side of a river.   Any works, including clean-up projects, require permits from the DEP and municipally run Local Inlands Wetlands Boards.”

The sustained cleanup effort and the new development regulations have had a profound effect on the health of the Naugatuck.   Stretches of the river are now stocked with brood stock Atlantic Salmon and a trout management area has been established.   The river is once again a popular fishing destination and today bald eagles, osprey and herons are returning to fish along its banks.   Recreational activities have also increased as the threat of harm from pollution has receded.

In the final article in this series we will look at the importance of forests to the ecosystem and how all of the seemingly unrelated aspects we have discussed so far, are all intricately interconnected.